Custom carrier board for EDGE

We are designing a custom board for Khadas Edge, unfortunately, I was not able to find any info regarding the pinout of MXM3 connector on the Captain - only information about pinout is in the schematic of the Captain board and in the schematic of the EDGE, but where on the connector do you physically have pin P1, S1, P75, P76? What is the order of the pin numbering? Connector pin numbering is not an industry standard and I think that the manufacturer should provide this information.

What are the pin types (input/output/pin mux), power (voltage, amps) specification of individual supply rails, info about internal pull-ups/downs… I am generally asking for some hardware documentation that does not suck. Hopefully some design guides.

I downloaded .brd file of the captain board, opened it in Allegro free physical viewer, but it does not contain any information. Just outline of the PCB and position of the MXM3 connector. Pin names/numbers are not visible.

Are you able to provide any of this information? Thank you.

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@Totti please follow up

Could you please, if not anything else, share the pin numbering order and physical pin numbers of the MXM3 connector?

Thank you :slight_smile:

Sorry, I have no time to deal with it today. I will reply to you tomorrow

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Sorry for the late reply, I just updated the DXF file and uploaded the to here.

Regarding these electrical properties and definitions, we have specifications for RK3399, which you may need to find by yourself.

The spec doesn’t appear to have been uploaded yet, so I’ll check with Gouwa to see if we can open it up

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Thank you very much. It would be nice to have some kind of design guide (PDF), which includes all of this information so people who would like to create their own boards have it in one place so they do not have to reverse-engineer everything (yeah, it is possible to estimate pin numbering from schematic and PCB with multimeter, but you know…). Just a tip. :slight_smile:

Have a nice day.

On this same topic, we are also developing a custom carrier board for the edge.

We are having issues routing ethernet from the gold fingers. Should we be routing it as 100 Ohm from gold fingers to the magnetics?

Is there any way of knowing what the impedance is from the PHY to the gold fingers, assuming gigabit ethernet?


@Totti please follow up

A 100 ohm impedance is required for these sets of difference lines;